This invention relates to surgery and more particularly to a tubular working sheath and obturator and to a method for using the same.
In several kinds of surgical operations, e.g., urological procedures, it is the current practice to insert and remove various instruments through the urethra several times during a single surgical operation. The repeated insertion and removal of instruments often requires a significant amount of force. This can of course traumatize the tissue. It is therefore a general object of the present invention to eliminate the need for inserting and removing a series of surgical instruments by passing them through an opening in the body in a manner that can cause discomfort or injure the tissue and in that way reduce the possibility of bleeding, trauma, inflammation, infection, false passage, and long-term complications such as scarring.
In addition, the manipulation of a surgical instrument or other object that is partially or completely inserted into the body can also result in damage to the surrounding tissue. A more specific object of the invention is to minimize the possibility of damaging the tissue through either the manipulation or the repeated insertion and removal of instruments that have to be used in succession to complete a surgical operation. For example, in many urologic procedures a cystoscope is inserted blindly or under direct vision for evaluation and diagnosis. The cystoscope is frequently removed and another instrument then inserted for lavage, cauterization, extraction, lavage or surgery. Not infrequently, a series of such instruments are inserted in succession. Finally, at the conclusion of the endoscopic or percutaneous procedure, it is frequently necessary to insert a catheter to divert urine or a drain. The insertion and removal of each of these other instruments increases the chances for traumatizing or injuring surrounding tissue or even creating a false passage and losing access. Moreover, each time a body orifice, i.e., oral cavity, urinary, gastrointestinal tract or other opening is manipulated, the potential for bacteremia is increased. In short, tissue trauma can result from retrograde or antegrade passage instrumentation or removal of foreign bodies. Moreover, many endoscopic, percutaneous or laparoscopic instruments have a relatively small diameter working channel which limits the size of biopsy specimens. The small size limits the removal of such specimens or foreign bodies by necessitating multiple insertions and withdrawals. This prolongs the operation and is an additional source of tissue trauma. Finally, when one instrument is removed and replaced by a second instrument, positioning the distal end of the second instrument is inexact because there is nothing present to locate the second instrument at a predetermined stop point with respect to the position taken by the previous instrument.
While it is known in the art to use a sheath to facilitate the insertion of a small catheter into the body, as described for example in U.S. Pat. Nos. 4,581,025 and RE31,855, no provision is made for accommodating a series of surgical instruments including endoscopes, cauteries, or instruments used in removing tissue for biopsy. Moreover, no provision is made for holding the patented sheath in place nor is there any provision for introducing anesthetic or medication. Accordingly, it is a more specific object of the invention to provide a method and surgical instrument that can be placed percutaneously or transurethrally for facilitating both endoscopic surgery or cystoscopic procedures so as to ease the successive placement, manipulation and removal of various surgical instruments including relatively bulky or rigid instruments such as endoscopes, cautery instruments, cold knife scalpel instruments, and biopsy instruments without increasing the likelihood of bleeding, trauma, inflammation and long-term complications. Another object of the invention is to provide such an instrument with a provision for holding itself securely in place during use while permitting introduction of fluids, e.g, for irrigating the tissue or for anesthesia, etc., and for accommodating instruments that are larger than the lumen of the working sheath. Yet another object of the invention is to provide a method for using such an instrument.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims.
Briefly, the invention is concerned with a surgical instrument, comprising, a working sheath and obturator as well as a method for facilitating endoscopic examination and surgical procedures using such an instrument. The sheath is an elongated self-supporting tube with a lumen of sufficient size to accommodate other surgical instruments. During use, the instrument is placed into the body percutaneously or through a body passage into a body cavity, e.g., endoscopically through the urethra, trachea, esophagus or rectum, or into the peritoneal cavity. A removable obturator is provided in the lumen to facilitate insertion of the sheath into the body. Once inserted, the obturator can be removed. Following this, the sheath is not moved while the operation is being performed. An inflatable balloon is preferably provided on the distal end of the sheath to hold it in place and thereby prevent retrograde movement. A peripheral duct or channel is also preferably provided for introducing lubricants during insertion or anesthetic during the procedure. While the working sheath remains in the body, any of various instruments selected by the surgeon, including instruments that are larger than the lumen of the sheath, can be inserted and removed by being passed into the body through the lumen of the sheath while the sheath remains in a substantially fixed position, i.e., stationary. The sheath thus acts as an artificial protective lining for the body opening through which it is passed, e.g., the urethra, gastrointestinal tract, bronchial tract, or percutaneous opening. The sheath can be used to introduce anesthetic and optionally lubricants to reduce discomfort or pain during insertion. In addition, the sheath can be used, if desired, to locate the distal end of any of a series of surgical instruments at a selected stop point with respect to the position taken by a preceding instrument. This feature may be very helpful with procedures under fluoroscopic (x-ray) guidance.
The invention thus provides a working sheath which can be thought of as a temporary and removable artificial tract or liner that is placed through an opening in the body of the patient at the beginning of a surgical procedure to facilitate endoscopic evaluation and treatment of the urinary tract or other body cavity for minimizing trauma and patient pain. During use, it allows multiple insertions and removals, i.e., the interchange of endoscopic instruments, catheters, drains, etc. At its proximal, i.e., outer end, the lumen of the sheath has an entry port for instruments with a removable cap that provides a nipple seal to preclude backflow of fluid from the body after the obturator has been removed. The instrument can be placed into the urethra blindly with an obturator in the lumen or under direct vision, i.e., with a fiber-optic scope extending through the sheath to act as an obturator. In other words, the obturator itself can comprise a fiber-optic bundle for illuminating and viewing a body cavity through the sheath, both during the insertion of the sheath and thereafter.